The Silver Kodiak arrived today.
A quick inspection showed excess lube on the breech which is a sure sign of detonation in the compression chamber. That is a piston seal killer!
Breech seal is toast and a piece of seal is in the barrel. Pretty sure it's part of the piston seal.
I'll order parts after I take it apart as it is possible the piston is damaged.
I'm also thinking of replaceing the Spring with a Gas Piston.